Tenforde MW, Self WH, Adams K, et al. - Researchers sought to determine if vaccination with mRNA COVID-19 vaccines—mRNA-1273 (Moderna) and BNT162b2 (Pfizer-BioNTech)—is associated with reduced COVID-19 hospitalization, and, among patients hospitalized with COVID-19, with reduction in the progression to critical disease.

• A case-control study of 4,513 hospitalized adults in 18 US states; these comprised 1,983 case patients with COVID-19 and 2,530 controls without COVID-19.

• For full vaccination with an authorized or approved mRNA COVID-19 vaccine, hospitalization for a COVID-19 diagnosis compared with an alternative diagnosis was linked with an adjusted odds ratio (aOR) of 0.15.

• For full vaccination, progression to death or invasive mechanical ventilation was linked with an aOR of 0.33 among adults hospitalized for COVID-19.

• Overall findings suggest that patients with COVID-19 hospitalization and with disease progression are significantly less likely to have received prior vaccination with an mRNA COVID-19 vaccine, this is consistent with risk reduction among vaccine breakthrough infections.